gui: native libadwaita-free UI backend + dark shell; packaging/iso updates

- gui/ui: native GTK4 widget vocabulary (.tn-*) behind the ui.* seam,
  default backend now native; style_apple.css design language
- shell: sidebar/topbar/content all #0f0f0f in dark (matches eww panels)
- new pages: wine, online_accounts
- packaging: tanin-icons (accent folder theme), tanin-calendar, gtklock,
  taninux-gtk3-theme, flatpak install handler
- iso/distro: profile + manifest tweaks (ISO binary not included)

packaging/tanin-libadwaita/PKGBUILD

@@ -12,7 +12,7 @@ pkgdesc="TANINUX Fuji recolour for GTK4/libadwaita + GTK3 — light + dark, pill
 arch=('any')
 url="https://taninux.kgva.ch"
 license=('GPL-3.0-or-later')
-depends=('glib2' 'adw-gtk-theme')        # gsettings + GTK3 base theme for the recolour
+depends=('glib2')                         # gsettings; GTK3-Theme: taninux-gtk3-theme
 optdepends=('tanin-setup: seed the variant + start the color-scheme watcher on login')
 
 package() {